Lecture 6.1 Nicotine

desired effects of stimulants (1)

elation, euphoria; exciteent; increased alertness; increased energy; reduced fatigue

side effects of stimulants (1)

incrase BP and HR; dilated pupils; increased talkativeness, restlessness, irritability; erratic behaviour, mania; incomnia; reduced appetite; increased sweating; anxiety, paranoia, panic; increased aggressiveness.

tolerance of stimulants (2)

rapid

stimulants risk of physical dependence (2)

moderate

stimulants risk of psychological dependence (2)

high

stimulants fatal overdose potential (2)

moderate to high

stimulant routes of adminstration (3)

smoke, absorbed across skin and mucosal membranes of mouth and nose

stimulants duration of effect (3)

short (2hr half life)

neurotransmitter directly affected by stimulants (3)

acetylcholine (also dopamine)

tolerance of stimulants (3)

moderate/high

physical dependence of stimulants (3)

moderate/high

psychological dependence of stimulants (3)

moderate/high

stimulants withdrawal symptoms (3)

craving, irritability, headaches, increased appetite, abnormal sleep

stimulants schedule (3)

legal

forms of nicotine (6)

chewing tobacco, cigars/pipes, cigarettes, vaporizers, nicotine patch, nicotine gum

nicotine routes of administration (6)

oral through buccal membranes (e.g., chewing tobacco, cigars, pipes, nicotine gum), inhaled (e.g., cigarettes, vaporizers), transdermal (e.g., patch)

smoking rates in western vs developing nations (8)

declining in western nations, rising in developing nations

when do most smokers begin smoking? (10)

in adolescence

how many chemicals in a cigarette? (11)

around 8000

how long does a puff take to deliver nicotine to the brain? (12)

around seven seconds

what impacts absorption of nicotine? (13)

how densed the tobacco is packed, length of cigarette, characteristics of the filter, number of cigarettes smoked throughout the day, volume of smoke inhaled, pH of the tobacco.

biggest increase of absorption (13)

length and volume of a drag (how big, how long they hold it)

where in the body does nicotine travel? (14)

everywhere (e.g., brain, placenta, all body fluids, breast milk)

nicotine metabolite (15)

cotinine

metabolism of nicotine men vs women (15)

women have a faster metabolism since the enzyme expression is increased by estrogen

why are there menthol cigarettes (15)

menthol decreases the metabolism of nicotine

nicotine half life (16)

2 hours

how is nicotine eliminated (16)

its metabolite is mainly extreted through the urine

nAChRs (17)

Nicotinic acetylcholine receptor; ionotropic; in the brain and autonomic nervous system

composition of nAChRs (18)

varies; 5 subunits with a pore; most common in 3 beta-2 with 2 alpha-4 and has high affinity; some have all alpha-7 and is locatted presynaptically.

speed of high-affinity nAChRs desenitization (21)

rapid; cell cannot fire again until the nicotine is removed;

smoking’s effects ont he sympathetic and parasympathetic systems (22)

wide range of effects; arouses the brian to a state of increased alertness; increases heart rate and blood pressure; at high levels, relaxes muscles and triffers the release of endorphins, natural opiates the may reduce stress; reduce circulation to extremites; suppresses appetitie for carbohydrates

dual motivations for nicotine consumption (25)

direct reward/reinforcement pathway (via mesolimbic DA pathway), cognitive enhancement (via mesocortical DA pathway

nicotine cognitive enhancement in smokers vs nonsmokers (27)

may be present in nonsmokers; increases in smokers but animals show performance deficits when withdrawing from chronic nocotine treatment

nicotine reinforcement in females vs males (28)

females are more sensitive to nicotine reinforcement

nicotine reinforcement in adolescents vs adults (28)

Adolescents show greater nicotine reward and reinforcement compared to adults

pharmacodynamic tolerance of nicotine (30)

receptor desensitization is possible with acute use; receptor upregulation is possible with chronic use

states of compulsion to use tobacco (32)

wanting → craving → needing

6 month relapse rate of nicotine (32)

high (70-80%)

nicotine withdrawal symptoms (32)

anxiety, irritability/frustration, decreased heart rate, difficulty concentrating, increased appetite/weight gain, restlessness, cigarette cravings, depression/dysphoria

nicotine withdrawal throughout the day (33)

nicotine withdrawal timeline (34)

can begin as quickly as 3 hours after cessation of smoking; symptoms reach a peak around 1 week post-cessation, and will gradually diminish over several weeks

varenicline (36)

partial agonist at high-affinity nAChRs expressed in the VTA; stimulates the nicotinic receptor on dopamine neurons, minicking the effects of nicotine but to a lesser degree.

tabacco related deaths per year in Canada (37)

47,000

how many puffs per year for a pack-a-day smoker? (42)

at least 50,000